Say East Asia(China, Korea, Japan, Taiwan, and Mongolia) is one nation. Would this singular nation have the available resources needed to have the potential to become an autarky like the US?
China on its own has sufficient of everything to do this (except Uranium of which it has some, but renewables would seem to be able to replace that). It might not be able to grow technologically as quick as it is in the real world today without imports, but grow it would.
